$9.$ A property is currently let for $$85,000$ per annum, in advance, fixed for the remaining $4$ years of the lease. A current rental has been assessed at $$115,000$ per annum, in advance. Given that a normal rate of return is $11\%$ and that leaseholds have been selling in the area at $19\%$ determine:

a$.$ the tenants interest

b$.$ the owners interest

c$.$ marriage value $($if any$)$